Reading stress from solid solvers

https://github.com/precice/openfoam-adapter/pull/236 added the possibility to read forces, effectively enabling structure solvers (such as solidDisplacementFoam or solids4Foam) to use the adapter.

It would still be nice if the adapter could also read stresses (Stress). This should hopefully not be so complicated to implement, assuming it is relatively similar to the writing part.

This issue has been mentioned on preCICE Forum on Discourse. There might be relevant details there:

https://precice.discourse.group/t/solids4foam-openfoam-fsi-coupling-cant-use-stress-as-the-exchange-data/2634/4